Parker 51 aerometric dating website
1051 Parker 51 Classic, burgundy with satin lustraloy cap, 14crt medium nib, pearlised cap jewel, aerometric filler, no dings or marks, uninked with original retailer chalk marks, 1960s, English, (mint). 1136 Parker 51 Clustom, burgundy with rolled gold cap, 14crt medium nib, pearlised cap jewel, aerometric filler, no dings or marks, uninked example, boxed with original instructions, 1960s, English, (mint). 1091 Parker 51 Custom, black with rolled gold cap, 14crt fine nib, pearlised cap jewel, aerometric filler, no dings or marks, boxed with original filling & operating instructions, uninked with original retailer chalk marks, 1962, English, (mint). 955 Parker 51 Presidential Pencil, 9crt gold with wavy line decoration, hallmarked on barrel, cap and pocket clip, pearlised clip jewel, engraved ' F. C.', English, date mark unclear, no dings or dents, (very good).10168: Parker 51 Club button: large metal pin back, 3.55 cm in diameter, given to Parker dealers as part of a sales contest promoting the initial release of the Parker 51; rare, and probably even less commonly seen than the sought-after contest award pens.In 1950 a new system for the date coding was introduced where the two digits only indicated the year, not the quarter hence "50" means made in 1950, this system was used in the US until 1955 and in Canada a few years longer.. It has been assumed that Parker began marking some of their pens on the trim or cap bands to allow for dating in 1970.
But to reach a 93% visual accuracy compared to traditional gold plating, Parker uses a 3 micrometer layer of which 0.4 micrometer is 14K gold. Possibly anticipating the 1980 official start of date coding in France and the UK, this could have led to the presumption that the dating actually began in 1970, but proof of this has still to be found. The quarter marker changed in 1988 from E, C, L, I to III, II, I or none (last quarter) according to the below table. The stamp initially had three dots and for each quarter one dot was filed down leaving none for the fourth quarter. Since production was overlapping examples exist with either the imprint 28 or .8. Also, since this coding system extended over a decade, a pen marked 38 could be produced the third quarter either in 1938 or 1948.